#include
#define uchar unsigned int
uchar time;
void main()
{
TMOD=0x01;
TH0=(65536-50000)/256;
TL0=(65536-50000)%256;
EA=1;
ET0=1;
TR0=1;
while(1);
}
void T0isr() interrupt 1
{
TH0=(65536-50000)/256;
TL0=(65536-50000)%256;
time++;
time%=20;
if(time==0)led1=!led1;
}